Rotary compressor



Oct. 16, 1934. BADGER 1,977,109

ROTARY COMPRESSOR Filed Aug. 5, 1952 Harry Mfiad yer MM M Patented o... 16, 1934 UNITED STATES ROTARY COMPRESSOR Harry M. Badger, Great Barrington, Mass., as-

signor to Landers, Frary & Clark, New Britain, Oonn., a corporation of Connecticut Application August 5, 1932, Serial No. 627,585

3 Claim.

This invention relates to rotary pumps or compressors of the type having a generally cylindrical casing within which is eccentrically mounted a revolving piston or roll of lesser diameter 3 than the cylinder wall, the crescent-shaped space between the cylinder and the piston being divided upon each revolution of the eccentric into a suction or intake compartment and a compression compartment by a partition which may be in the form of a blade. Pumps of this sort are particularly adapted for use as compressors in refrigcrating apparatus but are not specifically limited to that use.

A general aim of the invention is to provide ll an improved and simplified rotary compressor of this type wherein the bearing surfaces are maintained in a properly lubricated condition.

More particularly, an aim of the invention is to provide an improved rotary compressor or N pump wherein bearing surfaces between relatively moving parts are maintained in properly lubricated condition by the pump itself and without the use of any additional oil pumping device.

A further aim of the invention is to provide an improved and simplified compressor or pump of this type wherein wear between the piston and cylinder is automatically taken up and an effective seal is maintained between the ends 01' the piston and the end walls of the cylinder in which the piston is located.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplifiezi in the construction hereinafter set forth and .the scope of the application of which will be indicated in the appended claims.

In the accompanying drawing, wherein is shown, for illustrative purposes, one of the embodiments which the present invention may take,

Fig. 1 is a vertical sectional view through a compressor or pump made in accordance with the present invention, this view being taken substantially on line i-1 of Fig. 2;

Fig. 2 is a transverse sectional view taken substantially on line 2-2 of Fig. 1 and Fig. 3 is a sectional view taken on line 33 of Fig. 1, the rotary piston being shown by full lines in end elevation at the beginning of a stroke, and by broken lines in its first quarter position.

, Referring to the drawing in detail, A denotes generally the casing for the compressor, the same having a bore or cylinder with a generally circular wall 10 and opposed side or end walls 11 and 12. This casing may be of any suitable construction, it being shown as comprising two parts by way of illustration only. The casing has alined concentric bearings 13 and 14 in which is journalled an eccentric Bhaving an eccentric portion 15 located within the cylinder. Mounted upon the eccentric portion, for relative rotary movement, is a generally cylindrical piston roll or drum C of lesser diameter than the cylinder wall 10. The piston is substantially tangentially arranged with respect to the cylinder wall, and this point of tangency progresses about the cylinder wall when the eccentric is turned, there being opposite the point of tangency a crescent-shaped space. The compressor or pump is provided with an intake opening or port 16 and a closely adjacent but slightly angularly spaced outlet port 14 and, while these ports may take any suitable form, they are shown as comprising openings extending through the peripheral wall of the casmg. Between the intake 16 and outlet 1'? and adapted to divide the crescent-shaped space between the cylinder and the piston into an intake compartment 18 and a compression compartment 19 is a suitable partition which is adapted to move relative to the casing element or the piston element. This partition may take various forms but is here shown as having a blade 20 extending longitudinally of the piston and generally radially thereof. The blade has a barrel portion 21 35 located for oscillatory movement in a cylindrical recess 22 in the interior wall of the cylinder. The piston has a radially disposed longitudinally extending notch 23 the parallel side walls of which are spaced apart so as to more or less closely but slidably receive the blade 20. The intake port 16 may, for example, be operatively connected up to the refrigerating coil of a. refrigerator and the outlet port 17, which is preferably valved as well understood by those in the art, maybe connected up to the condensing means of the refrigerating apparatus. The compressor may be located within an oil case in such manner as to divide the oil case into a high compression chamber and a low compression chamber. As this arrangement is old, it is not illustrated in detail. However, a portion of an oil case D is shown in Fig. 2 in order that the improvements of the present invention may be more clearly understood. The showing of the oil case is more or less diagrammatic. It is understood by those familiar with the art that as the eccentric shaft is rotated the refrigerant,

or other medium, will be drawn into the intt're compartment 18 (as from the refrigerating coil of a refrigerator) and will be compressed in the the periphery of the eccentric.

compression chamber 19 from which it issues into the high compression side of the refrigerator apparatus. As the eccentric is turned, there is a relative reciprocating movement between the blade and the piston whereby the space behind the blade and in the bottom of the notch 23 will alternately decrease and increase. It may be stated here that the relation of the blade or partition to the two main elements of the compressor, namely, the cylinder and the piston, may be reversed, the construction shown in the drawing being by way of illustration only.

In accordance with the present invention, the relative movement between the blade or partition and the piston is employed for pumping a lubricant to the parts requiring the same. Leading upwardly through the casing is an oil inlet duct 30 having a port 31 opening into one end face of the cylinder bore at a point where during a portion of a revolution of the piston, the port will be in communication with the space in the notch 23 behind the blade 20 and during the remaining portion the port will be blanked by the piston. The inlet duct communicates at its lower end with the oil reservoir within the oil case D. The eccentric shaft has a longitudinally extending oil hole or bore 32 which is traversed by a hole 33 in the eccentric portion 15. The opposite ends ofthis hole 33 are connected by a groove or channel 34 in the periphery of the eccentric and passing halfway thereabout. The piston has an oil outlet duct 35 in the plane of the groove 34 and extending from the bottom of the notch 23 to The eccentric shaft has oil holes 36 leading from the bore 32 to the respective bearings 13 and 14 for the shaft. It is, of course, understood that the lubricant may be pumped to other'surfaces than those shown.

With this arrangement, during a portion of the revolution, say during the first half of a stroke of the piston (that is, from the full line position shown in Fig. 3 to that shown in Fig. 2) the oil outlet duct 35 is blanked by the eccentric; the inlet port 31 is uncovered, that is, it is in communication with the notch, and the piston is moving away from the blade so that the oil will be sucked from the oil reservoir through the duct 30 and into the notch behind the blade. On the second half of the stroke of the rotary piston, the inlet port 31 will be blanked by the piston; the outlet duct 35 will communicate with the channel or groove 34 of the eccentric, and the piston will move towards the blade so that the space behind the blade will gradually decrease, which means that the oil which has been sucked into that space will be forced into the bore 32 of the eccentric shaft and through the oil holes 36. The lubricant will also be supplied to the bearing surfaces between the eccentric and the piston. It will be seen from the foregoing description, taken in connection with the accompanying drawing, that the lubricant will be properly supplied to the several bearing surfaces or other parts requiring a lubricant by the action of the piston with respect to the blade or partition and without the introduction of any additional moving elements to the compressor. The oil pumping feature may be embodied in the compressor at very little additional expense.

In order to automatically take up wear between the piston and bore of the cylinder and to prevent leakage of the medium operated upon between the ends of the piston and the end walls of the cylinder, the peripheral wall 10 of the cylindcr and the periphery of the piston are correspondingly tapered, and there is provided a spring sealing ring 40 between the larger end of the piston and the opposed cylinder wall. In the present illustrated disclosure, the longitudinal taper of the piston and cylinder wall is somewhat pronounced, it being understood that in actual practice this taper is but very slight. The larger end of the piston has a groove 41 with an outer wall 42 which tapers inwardly toward the axis of the piston. The'sealing ring 40 is split, as at 43, so as to accommodate the blade and its'outer periphery is inclined or tapered correspondingly to the l tapered wall 42 of the groove 41. The outer face of the ring is adapted to engage the end wall 12 of the cylinder. With this arrangement, it will be observed that as wear occurs between the cylinder and-the piston, the spring ring 40 (which normally tends to expand radially) will, through its camming action on the inclined wall 42 of the groove 41, urge the pistontowards the left, referring to Fig. 1. The smaller end of the piston is resiliently urged by the ring against the end wall 11 of the cylinder and the ring itself resiliently engages the end wall 12 of the cylinder so that 00 leakage between the ends of the piston and the opposed end walls of the cylinder is guarded against without introducing any objectional frictional forces.

As many changes could be made'in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. A rotary pump including a cylinder element, a piston element eccentricallyand tangentially mounted in and of smaller diameter than said cylinder element and having a notch in its periphery, an eccentric shaft for eccentrically moving one of said elements relative to the other, said shaft having bearing surfaces, a bladejor dividing the space between said elements into an intake compartment and a compression compartment, said blade being connected for oscillatory movement to said cylinder element and having its inner end slidably engaging in said notch, an oil inlet port in said cylinder element for admitting a lubricant to said notch behind said blade, said port being blanked by said piston element during a portion of the cycle of movement of the piston and being uncovered during the remaining portion, and an outlet duct leading from said notch to the periphery of said eccentric shaft, said outlet duct being open while the nlet port is closed and said outlet duct being closed by 1 said shaft when the inlet port is open.

2. A rotary pump including a fixed cylinder,

a piston eccentrically mounted therein and of smaller diameter than said cylinder, there being a crescent-shaped space between said cylinder and piston, a shaft for eccentrically moving said piston to thereby progress said space about the interior of the cylinder, said shaft having oil holes and said piston having a notch in its periphery, a blade connected to the cylinder and slidabiy engaging in said notch, an inlet port in the end wall of the cylinder with which one end of the piston is in engagement, said port opening into said notch while the piston is moving away from the blade, said piston covering said port while the piston is moving towards the blade,

I and an outlet duct leading from said not-ch to said shaft, said outlet duct being in communication with said 011 holes while the piston is moving towards the blade, and said duct being blanked by the shaft while said inlet port is open.

3. A rotary pump having a cylinder element,

a piston element eccentrically and tangentially mounted in and or smaller diameter than said cylinder element and having a notch in its periphery, an eccentric shaft for eccentrically moving one of said elements relative to the 3 other, said shaft having bearing surfaces, a blade for dividing the space between said elements into an intake compartment and a compression compartment, said blade being connected for oscillatory movement to said cylinder element and having its inner end slidably engaging" in said notch, said cylinder element having an end race against which one end 01 said piston 

